Updated at 2 p.m. ET
Russian opposition figure Alexei Navalny was poisoned with a variant of Novichok, a Soviet-era nerve agent, according to tests carried out by a German military laboratory. A German government spokesman said the evidence is "without a doubt."
Navalny "is the victim of a crime that intended to silence him," German Chancellor Angela Merkel said during a news conference Wednesday about the findings. The crime, she said, was an "attempted murder."
Novichok is the same nerve agent used to poison former KGB spy Sergei Skripal and his daughter, Yulia, in a 2018 attack in Britain that Western nations have blamed on Moscow.
The Novichok group of nerve agents was "developed in a top-secret laboratory in Moscow and was once a closely held secret of the Russian government," as NPR's Geoff Brumfiel has reported. The name means "newcomer" in Russian — the chemical weapons were developed in the last years of the Cold War in a bid to create agents that were both lethal and difficult to detect.
Steffen Seibert, a spokesman for Merkel, said that Germany condemns the attack on Navalny in the strongest possible terms and urges the Russian government to explain what happened.
Navalny, 44, is one of Russian President Vladimir Putin's most prominent critics and has investigated well-placed officials over potential instances of corruption and abuse of office.
He fell ill on a commercial flight to Moscow from the Siberian city of Tomsk on Aug. 20, forcing the plane to make an emergency landing. Navalny's spokesperson, Kira Yarmysh, said she saw him drink one thing: a cup of tea at the airport in Tomsk.
Two days later, the activist and politician was airlifted from Siberia to the Charité hospital in Berlin. Navalny remains in a medically induced coma, but in a recent update, German doctors said his condition is stable and that his life is not in danger.
When Navalny was being treated in Siberia, doctors claimed there were no traces of poison in his system. They said he was suffering from a blood sugar imbalance.
Russian officials have called for caution in discussing what happened to Navalny, dismissing "premature and unsubstantiated accusations" about the presence of poison in his system.
Putin's press secretary, Dmitry Peskov, said last week that the Kremlin did not see any grounds to launch a criminal probe into Navalny's condition despite German doctors' initial findings he had been poisoned. But one day later, Putin "expressed interest in a thorough and impartial investigation of all the circumstances of the incident," the Kremlin said.
Now that Germany announced it has identified the poison, Peskov said Russia is ready for a full exchange of information about the case – but he reiterated that before Navalny left for Germany, an analysis in Siberia had found no toxic substances, according to the state-run Tass media outlet. Peskov also said the Kremlin cannot fully respond to the new allegations until German authorities share their data.
Merkel's office said the government is hoping Navalny will make a full recovery.
Navalny "continues to be treated in an intensive care unit and remains on a ventilator," the Charité hospital said Wednesday. "Recovery is likely to be lengthy. It is still too early to gauge the long-term effects which may arise in relation to this severe poisoning."
Germany will notify the Organization for the Prohibition of Chemical Weapons about the nerve agent's use, Merkel said. She added that Germany will also inform NATO and the European Union about the new allegations against Russia and that the organizations will discuss "an appropriate and joint reaction."
Both Sergei and Yulia Skripal survived the March 2018 attack in Salisbury, England, and the U.K. charged two Russian men with the crime. Then-Prime Minister Theresa May said that the U.K.'s security and intelligence agencies determined the men were "officers from the Russian military intelligence service, also known as the GRU."
Four months after the Skripals were poisoned in Salisbury, two local residents came into contact with Novichok, and one of them later died. U.K. authorities have said the two likely were exposed to the nerve agent that had been discarded after the March attack.
The Russian government has denied involvement in the Salisbury poisonings.
Esme Nicholson contributed to this report for NPR.